A new analysis has found that, among patients with chronic lymphocytic leukemia (CLL), African Americans more commonly present with advanced disease and tend to have shorter survival times than whites despite receiving the same care. These results suggest that biological factors may account for some racial disparities in cancer survival.
Among cancer patients, minorities tend to have a worse prognosis than whites. The reasons for this are unclear. In African American patients, lower socioeconomic status and limited access to high-quality care often can play a role, but some researchers propose that certain cancers can behave more aggressively in minority populations, which also can lead to worse outcomes.
Because CLL, a type of blood cancer, is rare in African Americans, investigators from The University of Texas M.D. Anderson Cancer Center in Houston and the Duke University Medical Center in Durham, North Carolina, led a study that combined the two centers’ experiences with African American and Caucasian patients. Their analysis included 84 African American patients and 1,571 non-black patients referred to the two centers. All patients, regardless of race, had access to health care services and received the same treatments.
“We sought to isolate race as a prognostic factor from other known demographic and clinical prognostic parameters in CLL,” explained Lorenzo Falchi, MD, of M.D. Anderson.
The investigators found that while the time from diagnosis (made either incidentally or because of clinical symptoms) to referral was shorter for African Americans than for white patients, CLL was more likely to be more advanced in African Americans at the time of referral. Also, although African Americans responded to first-line therapy as well as non-black patients, their cancer progressed more rapidly and their survival was shorter. The inferior survival of African American patients persisted when patients were grouped according to factors related to the severity of their disease. The study was published in Cancer (2013; doi:10.1002/cncr.28030).
“These findings suggest that while inducing similarly high response rates, standard treatments do not overcome racial differences in outcome among patients with CLL,” said Alessandra Ferrajoli, MD, also of M.D. Anderson. She added that a number of questions remain unanswered. For example, do distinct biologic characteristics of African American patients with CLL account for the disparities seen in this study? And will these findings hold in the general population, where the impact of socioeconomic status may be more varied?
In an accompanying editorial, Christopher Flowers, MD, of Emory University in Atlanta, Georgia, and Barbara Pro, MD, of Thomas Jefferson University in Philadelphia, Pennsylvania, noted that to adequately study disparities in leukemia, investigators will need to collect specimens and clinical data from patients to examine the potential impact of molecular and biologic markers. “Future studies in CLL can use this work as a cornerstone for investigating racial disparities in this disease,” they wrote.